Of course there is some theory. The one time I made use of stratified sampling I relied on William G. Cochran's "Sampling Techniques" (1977) published by Wiley & Sons. Basically, you want to sample in proportion to the variance of the variable of interest. In this way your sample is likely to be more informative.
Good luck,
Eric
>Hi,
>
>I am teaching a sophomore social statistics course.
>I've been covering sampling, especially stratified
>sampling this week.
>
>The students need some assistance in explaining the
>weighting procedures associated with disproportionate
>stratified sampling. How can I demonstrate this in a
>class with a concrete example.
>
>Also, is there any guidelines as to how to oversample
>a particular stratum? Assuming i have 2 groups (males
>are 20% and Females=80%). If I am drawing a sample of
>100 students - it means I would end up with 20 males
>and 80 females. If i need to oversample the males,
>what values should i chose - 30, 40, 50? - is the
>choice really arbitrary or is guided by theory or
>calculations?
>
>I will appreciate your thoughts on this.
>
>Regards, YC
--
===================================================
Eric G. Wruck
Econalytics
2535 Sherwood Road
Columbus, OH 43209
ph: 614.231.5034
cell: 614.330.8846
eFax: 614.573.6639
eMail: [email protected]
website: http://www.econalytics.com
====================================================
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
